TempStr = input("请输入带有符号的温度值")
if TempStr[0] in ['F','f']:
    # C = (eval(TempStr[0:-1])-32)/1.8
    C = (eval(TempStr[1:-1])-32)/1.8
    print("转换后的温度是{:.2f}C".format(C))
# elif TempStr[-1] in ['C','c']:
elif TempStr[0] in ['C', 'c']:
    # F = 1.8 * eval(TempStr[0:-1])+32
    F = 1.8 * eval(TempStr[1:-1]) + 32
    print("转换后的温度是{:.2f}F".format(F))
else:
    print("输入格式错误")